The invention relates to improvements in heat transfer in electronic technology. More particularly, the invention concerns electrical assemblages, such as circuit boards, which reduce heat generated in ceramic xe2x80x9cchipxe2x80x9d components during service.
It is well known that overheating of electrical components, for instance components mounted on a circuit board, contributes to reducing the life of the component. Overall component reliability is also compromised by excessive overheating during service. As circuit boards become denser and contain components that have higher power output capacity, reliability problems become magnified for solder joints of the circuit board, particularly in xe2x80x9cchipxe2x80x9d ceramic type parts due to CTE (Coefficient of Thermal Expansion) differences.
The current trend in the industry is to either assume the reliability risk or to institute extremely expensive chip construction processes for removing excess heat. Both practices have proven undesirable from a cost management standpoint.
In a typical electronic package, the largest chip ceramic component, for instance the 2512 resistor, is the least reliable component on most circuit boards and the component most likely to fracture its solder joint due to thermal cycling. The thermal cycling occurs every time the component is used. It would, therefore, be desirable to cool this component during service to dramatically improve its useful life and reliability.
Therefore, a need persists in the art for a system and method of cooling electrical components, such as those mounted in circuit boards, during service that produces a component that is reliable, cost effective and has an extended useful life.
It is, therefore, an object of the present invention to provide an electrical component protected from deterioration due to overheating during service.
Another object of the invention is to provide such an electrical component that is considerably more reliable, has a longer useful life and is cost effective to build and use.
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a method of cooling heat-generating components arranged on a circuit board includes the step of providing a circuit board containing at least one heat-generating component mounted thereon. The heat-generating component has a characteristic junction temperature Tj to be reduced during service. Thus, means for reducing the junction temperature Tj of the component is provided in the electrical assemblage. A heat-removing element, preferably comprising a plurality of thermal vias, is adapted to the heat-generating component typically on either of first and second mating surfaces. A heat sink element is also cooperatively associated with the.heat removing element for transporting heat removed from the heat-generating component to the heat removing element thereby reducing the junction temperature Tj of the heat-generating component to a temperature T1, wherein T1 is less than Tj.
The present invention has numerous advantages over existing developments including reliability, cost effectiveness, ease of development, and increased component useful life. Moreover, the present invention has the advantage of being applicable to practically any ceramic chip, ball grid array (BGA), direct die attached components, chip-on-board, and smaller chip resistors, such as the 2010, 1206, etc.